Occasions arise wherein a user of a first radiotelephone, such as a cellular telephone, desires to contact a user of a second radiotelephone who is known to be or believed to be roaming within a service area of the first user. For example, the first user can be in a service area within the Los Angeles area, while the second user may be an acquaintance or business associate from Miami who is known to be or believed to be in the Los Angeles area. Under conventional practice the first user can dial the number of the second user. A mobile switching center (MSC) that handles the call will recognize the area code for Miami and will route the call to a MSC in the Miami area. The Miami MSC will find from its Home Location Register (HLR) that the second user is actually roaming in the Los Angeles area, and will route the call back to the Los Angeles MSC. It can be appreciated that this technique is not efficient, and furthermore can result in the users incurring significant long distance charges for a call that may be required to go only a few blocks.
It is also known in the art to provide a two-stage dialing approach using local roamer access ports. These telephone numbers were known to be published (and may still be published) on a system by system basis throughout the United States. The result was a small book that was typically out of date due to area code changes, etc. In this system, one looked up the system and the area (there were only two systems in this method, not the seven that resulted from the PCS spectrum auction), then dialed that local number, then waited for a second dial tone, and then dialed the called party number. As can be appreciated, this technique also does not provide an optimum solution for contacting roaming users.